Low sex drive

For a while now I have been experiencing low sex drive and I think it has gotten worse. 😩 My SO & I use to have sex 1-3 everyday and as time passed that started going down now it's to the point where it's 1 time a day , 3 times a week but sometimes of those times I don't even wanna have sex I just do it because I don't want him to think that's it's not good because it is good it's just that my drive is low and I really don't know how to explain that to him. I feel like he's not gonna understand and take it the wrong way and think I'm just making excuses